This application is based on and incorporates herein by reference Japanese Patent Application No. 2001-111054 filed on Apr. 10, 2001.
The present invention relates to an accessory equipment driving device for a vehicle.
As a technology to improve fuel economy, a vehicle having an idle stop function that stops an engine at idle is proposed. In this type of vehicle, the idle stop function is canceled in order to drive a compressor for an air conditioner by the engine. Therefore, the idle stop function is not fully effective.
To counter this problem, a hybrid-compressor with an integrated motor is proposed in JP-A-2000-229516. This hybrid-compressor is driven by the engine when the engine is running. When the engine is not running, the compressor is disconnected from the engine and driven by the motor. To disconnect the compressor from the engine, a clutch mechanism, such as a one-way clutch or a clutch, is required. In other word, a motor and its driving control circuit, and a clutch mechanism are required. This increases complexity of configuration and a cost. Moreover, additional electrical circuits, such as an inverter circuit, to control a driving operation of the compressor are required.
Here, a power generating system (rotary electric machine and electrical circuit) can be simplified with a configuration in which the motor is driven to generate electricity.
An ideal condition of connections among the engine, rotary electric machine, and compressor for an air conditioner will be analyzed.
When the engine is started, the engine and the rotary electric machine need to be connected, and the compressor is better not to be connected with the engine nor the rotary electric machine (motor operation).
When the engine is running with the air conditioner off, the engine and the rotary electric machine need to be connected, and the compressor is better not to be connected with the engine nor the rotary electric machine (motor operation).
When the engine is running with the air conditioner on, the engine, the rotary electric machine, and the compressor need to be connected.
When the idle stop function is performed, the engine is better not to be connected with the rotary electric machine nor the compressor, and the rotary electric machine and the compressor need to be connected so that proper operations of the air conditioner are ensured.
In the accessory equipment driving device for a vehicle having an idle stop function, these connections need to be accomplished with simple configuration.
The present invention has an objective to provide an accessory equipment driving device for a vehicle with high installability to a vehicle, simple system configuration, and good cost efficiency.
An accessory equipment driving device for a vehicle of the present invention makes connections among an engine having an idle stop function, a motor-generator for a power generating operation and a motor operation, and accessory equipment such as a compressor for an air conditioner.
This device is for driving the accessory equipment by the engine when the engine is running, and by the motor-generator when the engine is idle. The device has an engine connecting shaft, a motor-generator connecting shaft, an accessory equipment connecting shaft. The shafts are to be connected to the engine, the motor-generator, and the accessory equipment, respectively.
The device has a torque distribution mechanism. This mechanism is for distributing engine torque inputted through the engine connecting shaft to the motor-generator connecting shaft and accessory equipment connecting shaft. It is also for transferring torque inputted through the motor-generator connecting shaft to the engine connecting shaft.
The device has a locking mechanism which locks the accessory equipment connecting shaft, and a clutch which disengageably connects the motor-generator connecting shaft of the torque distribution mechanism with the accessory equipment connecting shaft.
According to the above configuration, a single motor-generator can perform four different operations: a driving operation of the compressor when the idle stop function is performed, a starting operation of the engine by the motor-generator, a driving operation of the motor-generator by the engine, and a driving operation of both motor-generator and the compressor by the engine. Therefore, the motor-generator and its driving circuit can be integrated, and the configuration can be simplified.
Moreover, a motor-generator/accessory equipment system which consists of the compressor, motor-generator, torque distribution mechanism, clutch and locking mechanism can be separately placed from the engine. Therefore, a total shaft length of the engine can be reduced. This improves arrangement flexibility in an engine compartment, resulting in improved installability of the device, especially in small vehicles.